1. Technical Field
Embodiments of the present invention relate to an illumination apparatus. More particularly, embodiments of the present invention relate to a light emitting diode (LED).
2. Description of Related Art
In recent years, a light emitting diode (LED), which is eco-friendly, has been quickly replacing the conventional incandescent light bulbs and fluorescent lamps. Because the heat generated from the LED significantly reduces the lifetime and the illumination efficiency thereof, a chip-on-board (COB) LED is developed to lower the temperature during illumination. In the COB LED, a LED chip is directly mounted on a heat dissipation substrate for shortening the heat dissipation path, thereby lowering the temperature of the LED.
In a typical COB LED, the surface of the LED chip is covered by a wavelength conversion material for converting the wavelength of the light emitted by the LED chip.
However, under the limitation of the coating technique of the wavelength conversion material, most of the wavelength conversion material is coated on the top surface of the LED chip and only a few amount of the wavelength conversion material is coated on the lateral surface of the LED chip, such that the light emitted from the lateral surface of the LED cannot be converted, and differs from the light emitted by the top surface of the LED in wavelength. Therefore, a ring of the halation with different colors surrounding the LED chip is seen from the upper surface of the LED chip.